The present novel concept broadly relates to the art of cargo tanks and, more particularly, to a composite wall structure and a cargo tank trailer construction as well as a method of manufacturing the same.
Portable cargo tanks are typically designed and constructed to be suitable for transport using commonly available equipment and/or for movement within a predetermined space or envelope. For example, cargo tank trailers are constrained by various federal regulations regarding the size (e.g., length, width, height) and laden weight of the trailer. In some situations, the size limitations will dictate the quantity of product that can be transported. This is particularly true of bulky or low density products. In such situations, the weight of the fully loaded trailer often does not approach the weight constraints established by the federal regulations.
In many other situations, however, higher density payloads are being transported and the federal limitations on the laden weight of the trailer are determinative of the quantity of product that can be transported. That is, the combination of the empty (or tare) weight of the cargo tank trailer plus the weight of the quantity of product to be transported must be less than the maximum allowable laden weight established by the federal regulations. Since the empty weight of the cargo tank trailer is fixed, the amount of cargo that can be loaded will be limited to the difference between the maximum allowable vehicle weight and the tare weight of the trailer. As such, it is desirable to minimize the unladen or tare weight of the tank trailer to thereby maximize the payload that can be transported.
Attempts have been made to develop tank trailers having a reduced tare weight by using fiberglass reinforced composite material for the construction of the tank. While some reduction in the empty weight of tanks themselves have been possible using such constructions, other additional features and compartments have been included to form the tank trailer, and these additional features and components can significantly offset this weight savings. More specifically, known cargo tank trailers that are formed from a composite wall structure are formed from fiberglass material that is wound radially (also referred to as hoop windings) to form the body of the tank. Used alone, however, windings of this nature are generally recognized as being unable to withstand all of the load conditions to which the tank trailer will be subjected. As such, additional structural components are utilized to support the composite tank and carry the loads that known composite tanks are incapable of withstanding. Such additional structural components often take the form of a metal framework, which can include metal beams or other members that extend along the length of the trailer. The added weight of these components normally significantly offset any weight savings obtained from the use of the composite tank.
It is desirable to develop a composite wall structure, cargo tank trailer and method of manufacture that minimize or overcome the foregoing problems and disadvantages.